Alzheimer's disease (AD) is a neurodegenerative disorder of the central nervous system and the leading cause of a progressive dementia in the elderly population. Its clinical symptoms are impairment of memory, cognition, temporal and local orientation, judgment and reasoning but also severe emotional disturbances. There are currently no treatments available which can prevent the disease or its progression or stably reverse its clinical symptoms. AD has become a major health problem in all societies with high life expectancies and also a significant economic burden for their health systems.
AD is characterized by 2 major pathologies in the central nervous system (CNS), the occurrence of amyloid plaques and neurofibrillar tangles (Hardy et al., The amyloid hypothesis of Alzheimer's disease: progress and problems on the road to therapeutics, Science. 2002 July 19; 297(5580):353-6, Selkoe, Cell biology of the amyloid beta-protein precursor and the mechanism of Alzheimer's disease, Annu Rev Cell Biol. 1994; 10:373-403). Both pathologies are also commonly observed in patients with Down's syndrome (trisomy 21), which also develop AD-like symptoms in early life. Neurofibrillar tangles are intracellular aggregates of the microtubule-associated protein tau (MAPT). Amyloid plaques occur in the extracellular space; their principal components are Aβ-peptides. The latter are a group of proteolytic fragments derived from the β-amyloid precursor protein (APP) by a series of proteolytic cleavage steps. Several forms of APP have been identified of which the most abundant are proteins of 695, 751 and 770 amino acids length. They all arise from a single gene through differential splicing. The Aβ-peptides are derived from the same domain of the APP but differ at their N- and C-termini, the main species are of 40 and 42 amino-acid length. There are several lines of evidence which strongly suggest that aggregated Aβ-peptides are the essential molecules in the pathogenesis of AD: 1) amyloid plaques formed of Aβ-peptides are invariably part of the AD pathology; 2) Aβ-peptides are toxic for neurons; 3) in Familial Alzheimer's Disease (FAD) the mutations in the disease genes APP, PSN1, PSN2 lead to increased levels of Aβ-peptides and early brain amyloidosis; 4) transgenic mice which express such FAD genes develop a pathology which bears many resemblances to the human disease. Aβ-peptides are produced from APP through the sequential action of 2 proteolytic enzymes termed β- and γ-secretase. β-Secretase cleaves first in the extracellular domain of APP approximately 28 amino acids outside of the trans-membrane domain (TM) to produce a C-terminal fragment of APP containing the TM- and the cytoplasmatic domain (CTFβ). CTFβ is the substrate for γ-secretase which cleaves at several adjacent positions within the TM to produce the Aβ peptides and the cytoplasmic fragment. The 7-secretase is a complex of at least 4 different proteins, its catalytic subunit is very likely a presenilin protein (PSEN1, PSEN2). The β-secretase (BACE1, Asp2; BACE stands for β-site APP-cleaving enzyme) is an aspartyl protease which is anchored into the membrane by a transmembrane domain (Vassar et al., Beta-secretase cleavage of Alzheimer's amyloid precursor protein by the transmembrane aspartic protease BACE, Science. 1999 October 22; 286(5440):735). It is expressed in many tissues of the human organism but its level is especially high in the CNS. Genetic ablation of the BACE1 gene in mice has clearly shown that its activity is essential for the processing of APP which leads to the generation of Aβ-peptides, in the absence of BACE1 no Aβ-peptides are produced (Luo et al., Mice deficient in BACE1, the Alzheimer's beta-secretase, have normal phenotype and abolished beta-amyloid generation, Nat Neurosci. 2001 March; 4(3):231-2, Roberds et al., BACE knockout mice are healthy despite lacking the primary beta-secretase activity in brain: implications for Alzheimer's disease therapeutics, Hum Mol Genet. 2001 June 1; 10(12):1317-24). Mice which have been genetically engineered to express the human APP gene and which form extensive amyloid plaques and Alzheimer's disease like pathologies during aging fail to do so when β-secretase activity is reduced by genetic ablation of one of the BACE1 alleles (McConlogue et al., Partial reduction of BACE1 has dramatic effects on Alzheimer plaque and synaptic pathology in APP Transgenic Mice. J Biol Chem. 2007 September 7; 282(36):26326). It is thus presumed that inhibitors of BACE1 activity can be useful agents for therapeutic intervention in Alzheimer's disease (AD).
Furthermore, the formation, or formation and deposition, of β-amyloid peptides in, on or around neurological tissue (e.g., the brain) are inhibited by the present compounds, i.e. inhibition of the Aβ-production from APP or an APP fragment.
Inhibitors of BACE1 can in addition be used to treat the following diseases: IBM (inclusion body myositis) (Vattemi G. et al., Lancet. 2001 December 8; 358(9297):1962-4), Down's Syndrome (Barbiero L. et al, Exp Neurol. 2003 August; 182(2):335-45), Wilson's Disease (Sugimoto I. et al., J Biol Chem. 2007 November 30; 282(48):34896-903), Whipple's disease (Desnues B. et al., Clin Vaccine Immunol. 2006 February; 13(2):170-8), SpinoCerebellar Ataxia 1 and SpinoCerebellar Ataxia 7 (Gatchel J. R. et al., Proc Natl Acad Sci USA 2008 January 29; 105(4):1291-6), Dermatomyositis (Greenberg S. A. et al., Ann Neurol. 2005 May; 57(5):664-78 and Greenberg S. A. et al., Neurol 2005 May; 57(5):664-78), Kaposi Sarcoma (Lagos D. et al, Blood, 2007 February 15; 109(4):1550-8), Glioblastoma multiforme (E-MEXP-2576, http://www.ebi.ac.uk/microarray-as/aer/result?queryFor=PhysicalArrayDesign&aAccession=A-MEXP-258), Rheumatoid arthritis (Ungethuem U. et al, GSE2053), Amyotrophic lateral sclerosis (Koistinen H. et al., Muscle Nerve. 2006 October; 34(4):444-50 and Li Q. X. et al, Aging Cell. 2006 April; 5(2):153-65), Huntington's Disease (Kim Y. J. et al., Neurobiol Dis. 2006 May; 22(2):346-56. Epub 2006 January 19 and Hodges A. et al., Hum Mol Genet. 2006 March 15; 15(6):965-77. Epub 2006 February 8), Multiple Mieloma (Kihara Y. et al, Proc Natl Acad Sci USA. 2009 December 22; 106(51):21807-12), Malignant melanoma (Talantov D. et al, Clin Cancer Res. 2005 October 15; 11(20):7234-42), Sjogren syndrome (Basset C. et al., Scand J Immunol. 2000 March; 51(3):307-11), Lupus erythematosus (Grewal P. K. et al, Mol Cell Biol. 2006, July; 26(13):4970-81), Macrophagic myofasciitis, juvenile idiopathic arthritis, granulomatous arthritis, Breast cancer (Hedlund M. et al, Cancer Res. 2008 January 15; 68(2):388-94 and Kondoh K. et al., Breast Cancer Res Treat. 2003 March; 78(1):37-44), Gastrointestinal diseases (Hoffmeister A. et al, JOP. 2009 September 4; 10(5):501-6), Autoimmune/inflammatory diseases (Woodard-Grice A. V. et al., J Biol Chem. 2008 September 26; 283(39):26364-73. Epub 2008 July 23), Rheumatoid Arthritis (Toegel S. et al, Osteoarthritis Cartilage. 2010 February; 18(2):240-8. Epub 2009 September 22), Inflammatory reactions (Lichtenthaler S. F. et al., J Biol Chem. 2003 December 5; 278(49):48713-9. Epub 2003 September 24), Arterial Thrombosis (Merten M. et al., Z Kardiol. 2004 November; 93(11):855-63), Cardiovascular diseases such as Myocardial infarction and stroke (Maugeri N. et al., Srp Arh Celok Lek. 2010 January; 138 Suppl 1:50-2) and Graves disease (Kiljański J. et al, Thyroid. 2005 July; 15(7):645-52).
The present invention provides novel compounds of formula I′, their manufacture, medicaments based on a compound in accordance with the invention and their production as well as the use of compounds of formula I′ in the control or prevention of illnesses such as Alzheimer's disease. Furthermore the use of compounds of formula I′ in the treatment of amyotrophic lateral sclerosis (ALS), arterial thrombosis, autoimmune/inflammatory diseases, cancer such as breast cancer, cardiovascular diseases such as myocardial infarction and stroke, dermatomyositis, Down's Syndrome, gastrointestinal diseases, Glioblastoma multiforme, Graves Disease, Huntington's Disease, inclusion body myositis (IBM), inflammatory reactions, Kaposi Sarcoma, Kostmann Disease, lupus erythematosus, macrophagic myofasciitis, juvenile idiopathic arthritis, granulomatous arthritis, malignant melanoma, multiple mieloma, rheumatoid arthritis, Sjogren syndrome, SpinoCerebellar Ataxia 1, SpinoCerebellar Ataxia 7, Whipple's Disease and Wilson's Disease. The novel compounds of formula I′ have improved pharmacological properties.